1. I am somewhat reserved, so I don't talk too much.

Question

2. It's not easy to understand other's personality.

3. My friend's character is opposite to mine.

4. I and my friend are similar in character.

5. I am quite different from my brother in character.

6. Children have the qualities of the parents.

7. Flattery is foreign to my nature.

8. I'm kind of introvert.

9. I am rather extrovert.

10. She's got a great personality.

11. You have such a wishy-washy personality.

12. The twins have very different characters.

13. The novelist characterizes his heroine as passionate.

14. He is an emotional man [character, response]

15. He is rather a neutral character.

(Are the expressions above all grammatical? If you find any wron expressions, let me know. Thank you.)

Answer 1

2 - another's

4 - My friend and I...

8 - introverted

9 - extroverted

14 - man, person, character (all are fine)

All the rest are fine.